Akkad or the Akkadian Empire (Sumerian: Agade, Bible: Accad) was the oldest empire in history. It was located in Mesopotamia. The Akkadian empire reached its peak during the rule of Sargon of Akkad in the 24th and 22nd centuries BCE, and it eventually collapsed in 2154 BCE. The ruins have not been found, but it is believed to be on the River Euphrates. The empire comes after a long relationship with Sumer, and before the ethnic Akkadian empires of Babylonia and Assyria.